The present technology generally relates to coating systems and methods suitable for protecting articles or components exposed to high-temperature environments, such as the hostile thermal environment of a turbine engine. More particularly, the present technology relates to a coating that may serve as an oxidation resistant coating and/or as a bond coating to an environmental and/or thermal barrier coating.
Ceramic and refractory intermetallic materials and composites are currently being considered for such high temperature applications as combustor liners, vanes, shrouds, blades, and other hot section components of turbine engines, and for use in structures designed for service at high temperature in such applications as heat exchangers and internal combustion engines. Some examples of composite materials include silicon-containing composites, for example, composite materials in which silicon, silicon carbide (SiC), silicon nitride (Si3N4), and/or a refractory metal silicide serves as a reinforcement phase and/or a matrix phase. However, the environments characteristic of these applications often contain water vapor, which at high temperatures is known to cause significant surface recession and mass loss in silicon-bearing materials. The water vapor reacts with the structural material at high temperatures to form volatile silicon-containing species, often resulting in unacceptably high recession rates.